Pinpoint Test A: The Parking Brake Does Not Apply Or Does Not Hold Vehicle
- Normal Operation and Fault Conditions
When the parking brake control is pulled, the parking brake equalizer pulls on both rear parking brake cables, which are attached to the parking brake actuators, and applies the brake shoes/pads.
Possible Sources
- Parking brake cable(s)
- Parking brake control
- Rear brake caliper(s)
- Parking brake cable equalizer
- A1 CHECK THE PARKING BRAKE CONTROL
- Pull up the parking brake control handle.
Does the parking brake control move?
Yes GO to A2 No GO to A3 - A2 INSPECT THE FOLLOWING PARKING BRAKE COMPONENTSNOTE: Have an assistant pull and release the parking brake to help isolate disconnected cables or cables that do not move.
- Parking brake control
- Front parking brake cable
- Rear parking brake cables and/or equalizer
- Rear brake caliper actuators
Is any damage found or are any components disconnected?
Yes CONNECT the component(s) or INSTALL new parking brake component(s) as necessary. TEST the system for normal operation. ADJUST the parking brake cables. REFER to: Parking Brake Cable Adjustment . No VERIFY that the rear pads and brake discs are within thickness specifications. REFER to: Specifications . If the rear pads and brake discs are OK, INSTALL new rear brake caliper(s). REFER to: Brake Caliper - Vehicles With: Electronic Parking Brake (EPB) . - A3 ISOLATE THE PARKING BRAKE CONTROL AND FRONT PARKING BRAKE CABLE
- Disconnect the front parking brake cable from the rear parking brake cable equalizer.
- Pull up the parking brake control handle.
Does the parking brake control handle move?
Yes GO to A4 No INSTALL a new parking brake control or a new front parking brake cable as necessary. REFER to: Parking Brake Control . REFER to: Parking Brake Front Cable
. TEST the system for normal operation. - A4 ISOLATE THE REAR PARKING BRAKE CABLES
- Disconnect the rear parking brake cable from the rear brake caliper at the affected wheel end(s).
- While holding the cable conduit, attempt to slide the cable inside the conduit.
Does the cable slide freely inside the conduit?
Yes The parking brake system is operating normally at this time. INSPECT the rear brake components on the affected wheel end(s). INSTALL new rear brake components as necessary and ADJUST the parking brake cables. REFER to: Parking Brake Cable Adjustment . No INSTALL new rear parking brake cables. REFER to: Parking Brake Rear Cables .